Some niggling problems were fixed outright. It always bugged me in previous Civs that you were rewarded for building roads in every single tile. In Civ V, roads and some other improvements have a maintenance cost so you need to pick and choose what your workers build wisely. Thankfully, you don't have to connect each resource with a road anymore, merely building the corresponding improvement within your borders does the trick. Finding strategic resources Iron and Horses is doubly important now because each resource only lets you build a finite number of units. For example, building a mine on an Iron tile might only net you two Iron, from which you can only build two Swordsmen. It's a brilliant system, because it forces the kind of strategic decisions that Civ is all about.
The biggest change is, of course, the use of hexes instead of squares. After the first couple of turns, I hardly noticed the difference. Hexes work just fine and your brain learns to adapt quickly.
The effect that hexes have on combat pales next to the fact that units no longer stack in Civ V. It changes combat drastically, and for the better. Fighting with varied units arrayed on the field is not only encouraged, it's damn well necessary if you are going to have any success. You consider whether to flank with Horsemen and wait to attack with your frontline Swordsman until you have supporting Archers in place. And that's just awesome.
The modern era units are just as fun and even more varied than their ancient counterparts. Combat with Bombers, Submarines and Tanks feels more like a Rock-Paper-Scissors affair with Destroyers, Fighters and Anti-Tank Guns designed to take out specific units. Because cities have an innate defense, bombarding is necessary, and I liked using Bombers and Artillery to soften up Paris before I sent in my Giant Death Robot. I know that the GDR has a penalty attacking cities, but I couldn't resist stomping on the French with my robot. Perhaps I'm permanently scarred from their garish pink units constantly attacking me in Civ 2.
I was surprised that after playing through Civ V about ten times that I usually won a conquest victory by destroying all the capitals of the other civs out there. Historically, I built a spaceship and won that way. It's a testament to the combat system in Civ V that I had way more fun building units and attacking my neighbors than I did with previous versions. Lead Designer Jon Shafer did a great job revamping an old franchise and infecting it with new ideas to make it still seem fresh. I love Civilization V and will likely spend hundreds of hours over the next few years taking over the world.
Bottom Line: My favorite Civilization to date. Hex tiles and no stacking makes combat fun and more tactical. The new systems work incredibly well without altering what makes the game Civilization. Civ V is an excellent game.
Recommendation: Go to Steam and buy it right now. Do it.
Greg Tito would like to thank all of the dead barbarian brutes and French musketeers who made this review possible.